User Manual

Ordering and delivery
When ordering, please give name and type reference, e.g.
Differential pressure sensor QBM65-3/C
The differential pressure sensors are supplied with a round connector (type: Lumberg
RKC 30/11) and a 2m plastic tubing.
.
Additional accessories are to be ordered separately.
Accessories
Two sets of air duct probes are available for precise measurements, see datasheet
CA1N1589E for details. Mounting brackets are available additionally.
Name Type reference
AQB2000
Mounting bracket for mounting the sensor on lagged duc
ts
AQB21.2
Bracket (5 pieces) for top hat rails to DIN, HT 35-7.5
FK-PZ1 Air duct probe, short, stainless steel, with elastic lead-through for
simple, quick and airtight mounting
FK-PZ2 Air duct probe, long, aluminium, with orifice plate for precise
measurements
Equipment combinations
The QBM65.../C differential pressure sensor can be used in combination with all de-
vices or systems capable of handling its DC 0...10 V output signal.
Type QBM75.../C can be used with all devices or systems capable of handling its
DC 4…20 mA output signal and having a power supply in the range of DC 11…33 V
(2-wire connection).
Mode of operation
The differential pressure sensors use a silicone-rubber diaphragm to register changes
in pressure. The deflection of the diaphragm is registered by the ceramic lever and
converted into an electrical signal.
This signal is conditioned by the built-in electronic circuit to give a linear DC 0...10 V, or
DC 4…20 mA signal representing the measured value.
Mechanical design
The differential pressure sensors comprise the following:
• Sensor housing with integral 3-core connector and hinged cover
• Pressure casing with diaphragm and lever
• Printed circuit board
• Digital display for sensor signal in Pa (only with the QBM75.1-1/C)
Mounting and installation notes
Mounting instructions are enclosed with the differential pressure sensors.
The differential pressure sensors are suitable for direct mounting on ducts, walls or
ceilings and in control panels. Note that the sensors must be mounted vertically.
Where possible, the pressure connection nozzles should be at the bottom, or if neces-
sary, to the side, and they should always be higher than the duct probes.
2/6
Siemens Differential pressure sensors QBM65…/C, QBM75…/C CA1N1919E
Building Technologies 27.08.2010